The numbers are there, they just aren't listed by the default print method for density. When you type the object name, den0, R runs print.density(den0) which provides summary statistics. You need to look at the manual page (?density) and pay close attention to the section labeled "Value" which provides information about what values are returned by the function.
str(den0) den0$x den0$y plot(den0$x, den0$y, typ="l") ---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of li li > Sent: Wednesday, August 08, 2012 9:03 PM > To: r-help > Subject: [R] Density > > Dear all, > Given a set of observations X, I want to evaluate the kernel density > estimator > at these observed values. If I do the following, I do not get the those > estimated values directly. > Can anyone familiar with this give an idea on how to find out the > estimated > density values for X? > > > X <- rnorm(100) > > > density(X)-> den0 > > > den0 > > > Call: > > density.default(x = X) > > > Data: X (100 obs.); Bandwidth 'bw' = 0.354 > > > x y > > Min. :-3.2254 Min. :0.0002658 > > 1st Qu.:-1.6988 1st Qu.:0.0359114 > > Median :-0.1721 Median :0.1438772 > > Mean :-0.1721 Mean :0.1635887 > > 3rd Qu.: 1.3545 3rd Qu.:0.2866889 > > Max. : 2.8812 Max. :0.3776935 > > > I did write the code for the kernel density > > estimator myself. So once I find a proper bandwidth, > > I can use the following function. However, it would be nicer > > if there is a more direct way. > > > > fhat <- function(x, X){ > > + h <- density(X, bw="SJ")$bw > > + n <- length(X) > > + 1/(n*h)*sum(dnorm((x-X)/h))} > > > > > > est <- numeric(length(X)) > > > for (i in 1:length(X)){est[i] <- fhat(x=X[i], X=X)} > > > > > > est > > > > > Thanks in advance. > > Hannah > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
